Correlation between diastolic function and maximal exercise capacity on exercise test

Area of Science:

• Cardiology
• Exercise Physiology
• Diagnostic Imaging

Background:

• Pulmonary capillary pressure (PCP) elevation contributes to exercise intolerance.
• Echocardiography (ECHO) allows for diastolic function assessment and PCP estimation.

Purpose of the Study:

• To identify determinants of exercise capacity in patients undergoing exercise testing (ET) and echocardiography (ECHO).
• To evaluate the role of conventional ECHO and tissue Doppler imaging (TD) in assessing exercise capacity.

Main Methods:

• Retrospective study of 640 patients undergoing ET, ECHO, and TD, excluding those with ejection fraction < 55%.
• Mitral annulus velocities (E, A, e', a') were measured; E/e' > 10 indicated increased PCP.
• Exercise capacity was quantified by metabolic equivalents (METs); patients were grouped as MET < 7 or MET > 7.

Main Results:

• A higher proportion of patients with E/e' > 10 (41.7% vs 9.4%) and diastolic dysfunction (76.6% vs 34.1%) were in the low exercise capacity group (MET < 7).
• Logistic regression identified age, female gender, and late diastolic velocity (A) as independent predictors of low exercise capacity (MET < 7).

Conclusions:

• Echocardiography-determined diastolic dysfunction is associated with reduced exercise capacity.
• Female gender and older age are independent factors contributing to lower exercise capacity in a low-risk CAD population.